Kitten losing baby teeth

I did a search but didn't really find what I was looking for - apologies if this post was unneccessary.

My husband pointed out this morning that Libby looked like she was snarling and that it may be her tooth... I thought so too and to confirm it, I just found the tooth on the bedroom floor

I just wondered if there's anything i should be doing now for her. I mean, should I check her teeth to make sure everything's ok there, or take her to the vets to do it. Is it a problem if she swallows one? Will she be in pain/still able to eat her dry food?

I know this all sounds over the top probably - over-worrying... but this is my first cat ever and i'm not really sure! I'm glad I found these forums or I wouldn't even know that cats lost their teeth and would probably be freaking out right now, lol.

All normal, no need to worry
They normally do swallow them, so that's not really an issue.
Not much you need to do, just keep an eye on the fangs, sometimes the adult teeth will come in fully, and the baby fangs will still be there without even loosening up.
If that happens, keep an eye on the gums, if they look swollen or too red, a vet may have to help get the baby teeth out.

This does not normally happen though.

Cleo lost her last two baby teeth a few weeks ago. Of course i freaked out when i saw them on the bedsheet but she didn't cry in pain, i think she actually lost one while i was playing with her! She was eating and playing like normal.

Lily has lost some of her baby teeth over the past few days. Her breath has been stinkin' something awful for a month now, so I knew it was about time. With our other cats, I never saw any teeth. I figured they just swallowed them. But Lily's cute little teeth have been turning up in different rooms. I almost put one in a little tooth keeper and stuck it my drawer with my son's first tooth, but I decided that was a little much.

at what age do cats begin to lose their teeth?

My understanding is that it usually happens between 4 and 7 months of age.